Recently, functions of the portable device have been rapidly expanding, and such functions as seen in portable telephones, e.g. contents display on the Internet, function of sending and receiving mails, picking up and reproducing still pictures and moving pictures, have become established as the standard functions. In addition, for the still pictures and moving pictures, the high-definition pictures have been developed as a factor for differentiation, and high-performance image pickup elements have been developed and commercialized. In accordance with this, size of the data handled by a portable device goes on increasing.
Further, these portable devices not only record the contents of still pictures and moving pictures in an internal memory, but also record them in a detachable memory card. Thereby, transfer of the content to other portable devices or PC (Personal Computers) can be easily achieved, and various kinds of data within the portable device can be carried out of the device.
Furthermore, through using a memory card having a copyright protecting function also with respect to the content protected by the copyright, a method for recording to the memory card by encrypting the content is employed. Since a system has been employed that decrypts the encrypted content by using a medium ID that is the characteristic number of the memory card. Thus, decryption is difficult since it is not possible to duplicate the medium ID even though the encrypted content is duplicated to other memory cards. In this way, duplication of the content is controlled by the use of the memory card that has the copyright protecting function. As described above, “duplicating of the encrypted content to a memory card” is referred to as “checkout”.
Patent Literature 1 discloses a terminal device that receives encrypted content data and a license key from a distribution server. In this case, however, a memory card of a large capacity is also required since the encrypted content data is downloaded from the server so as to record it to the memory card.    Patent Literature Japanese Unexamined Patent Publication 2002-91827